Originally Posted by GAWnCA
I can think of quite a few places to buy worm gears, but they are EXPENSIVE. If you bought the gears, might as well just buy the table setup.
As far as the number of teeth on the gear goes, I think that it would be dictated by the TPI of the worm you use and the diamater of the table you intend to make. Bottom line is if it's to be used as a CNC'd axis and your microstepping, the number of teeth won't be much of an issue for accuracy. You could also just mimic another design.
Here's another thought on drilling the holes for the worm - consider that a 10tpi acme thread has a 4deg pitch; you could just tilt the head of your mill column 4deg and drill away, then the gashes would be perfectly set up to use. You also wouldn't think twice to form a cutter from a piece of 10tpi acme thread either :-)